Category: Administration / Server

the for loop when the user wants a command to be run exactly x times for i in $(seq 1 5); do echo $i; done # for example generate a file with 1 million lines # and messure the time […]

second take on trying to get a xmpp server (OpenFire, Java) client (Pidgin, C (C#, Perl, Python, Tcl are used for plugins)) up and running. at least this time with partial luck (was able to login via pidgin) but it […]

the nice: NAT is nice as it provides some form of protection/shielding of vms from the internet, by placing the host between (doing all the fire walling) the problem: server is exposed to regular dovecot and exim password bruteforce attempts, […]

versus is the wrong word. They are both great great GNU Linux distributions with a different focus and imho the perfect combination. Debian (apt based) “the universal operating system” (because has great hardware compatibility amd64 (64Bit intel) arm64 armel armhf […]

guess with it-security and internet-security (internet = roads, cars = computers that users use every day) it is like with real-life-security – there is no 100% security. all users of a system are in constant potential danger of having an […]

git is not only good for crowds of developers having to organize and sync “status quo” of the project over various devices, users also use it for version control of documents and various other files (anything where organized cooperation between […]

https://theintercept.com/2020/04/03/zooms-encryption-is-not-suited-for-secrets-and-has-surprising-links-to-china-researchers-discover/ hm…. let me think where one has seen this before: TELEGRAM! Zoom’s service is “not suited for secrets” “The researchers also found that Zoom protects video and audio content using a home-grown encryption scheme, that there is a vulnerability […]

Videos: ssh thanks for sharing even when the audio is pretty crappy. slides (hard to read on video) can be found here: https://degabriele.info/slides/SSH_CCS_16.pdf “dropbear” is ambedded ssh server Made in Australia (wiki) also available as Android App naming: a “dropbear” […]

this really raises the question: the mobile (complete computer) phone (number) as key to everything? is it a good idea to rely on smart phones (that are essentially a very small laptop and a cellular modem) and phone numbers to […]

hostnamectl; # tested on Icon name: computer-desktop Chassis: desktop Operating System: Debian GNU/Linux 10 (buster) Kernel: Linux 4.19.0-8-amd64 Architecture: x86-64 su – root; # become root apt update apt install rfkill rfkill list all 0: phy0: Wireless LAN Soft blocked: […]

the “perb” seems to be SELinux “missing context”. hostnamectrl; # tested on CentOS Linux 7 (Core) Kernel: Linux 3.10.0-1062.12.1.el7.x86_64 # with latest updates as available in 2020-02 As told above, try first: setenforce 0; # temporarily disable SELinux, can files […]

imho: CentOS is a rock solid server operating system. Why is CentOS perfect for servers? a server (usually) is build for a specific purpose and should have as little software installed as possible (more software = more reliability, speed and […]

the tech guy in this video says: his “smart” APC UPS – “battery exploded and leaked all over the place” have two UPS here one from APC and one from EATON. and the EATON 5PX. EATON 5PX 2200 pros and […]

# become root su – root; # rpm based yum install nmap # apt based apt install nmap # find snmp enabled devices # (UDP port 161, can not be tested with telnet (can only do TCP)) nmap -sU -p […]

# tested on hostnamectl CPE OS Name: cpe:/o:centos:centos:8 Kernel: Linux 4.18.0-147.3.1.el8_1.x86_64 Architecture: x86-64 # one could do just this: # yum install postgresql-server postgresql-contrib # will give one this version: # psql –version # psql (PostgreSQL) 10.6 # if one […]

the fast leight weight, secure and (used to be easy to configure) webserver lighttpd is currently not working under Fedora / RedHat / CentOS (7?) 8 because lighttpd (currently) can not bind at ipv4 while ipv6 is active (see). https://www.lighttpd.net/ […]

basically one column view of a specific directory without all the “-rw-r–r–. 1 owner group 734 Jan 15 20:16” clutter. ls -C1 /etc/lighttpd/conf.d/*.conf /etc/lighttpd/conf.d/access_log.conf /etc/lighttpd/conf.d/auth.conf /etc/lighttpd/conf.d/cgi.conf /etc/lighttpd/conf.d/cml.conf /etc/lighttpd/conf.d/compress.conf /etc/lighttpd/conf.d/debug.conf /etc/lighttpd/conf.d/dirlisting.conf /etc/lighttpd/conf.d/evhost.conf /etc/lighttpd/conf.d/expire.conf /etc/lighttpd/conf.d/magnet.conf /etc/lighttpd/conf.d/mime.conf /etc/lighttpd/conf.d/proxy.conf /etc/lighttpd/conf.d/rrdtool.conf /etc/lighttpd/conf.d/scgi.conf /etc/lighttpd/conf.d/secdownload.conf /etc/lighttpd/conf.d/simple_vhost.conf /etc/lighttpd/conf.d/ssi.conf […]

all infos about one’s harddisk: # tested on: hostnamectl Static hostname: centos.localdomain Operating System: CentOS Linux 7 (Core) CPE OS Name: cpe:/o:centos:centos:7 Kernel: Linux 4.15.9 Architecture: x86-64 # software needed: install smart monitoring tools yum install smartmontools.x86_64 # nice overview: […]

now WITH SPICY COMMENTS X-D SecurityLab, [22.12.19 12:40] A Twitter user using the alias 08Tc3wBB created tfp0-an exploit that allows you to jailbreak the latest iPhone models with IOS 13.3. The functionality of the exploit has already been confirmed by […]

firewall & pinguin: iptables where do thou go? it is said that when using “ip-sets” iptables and nftables achieve almost same performance (amounts of ips possible to block, without server becoming slow/unresponsive) Redhat and nftables on DDoS “so the only […]

situation: one is userA but wants to ssh login to server with ipv4: 123.123.123.123 via userB (dedicated user for that server/task). so what one does is: make sure one can login as userB than as userA: userA: ssh -v -i […]

very very nice actually. visit the site: https://www.wieistmeineip.de/ 1) setup an ssh server 2) make sure u can login with the given user ssh -N -D 9090 -p22 user@yourserver.com now config firefox proxy like this: click “ok” then visit the […]

what do you think about the CNBC documentary? 2012: Aalto Talk with Linus Torvalds: 1,5 Million Views! contains the famous “Fuck You NVIDIA” https://www.youtube.com/watch?v=MShbP3OpASA Linus Torvalds writes software since his early childhood ages and just loves programming. Without this love […]

list all current ips that are connected to port 587 netstat -anp | grep :587 | grep ESTABLISHED

Mozilla Firefox, Firefox Browser, or simply Firefox, is a free and open–source (src: Wikipedia) web browser developed by the Mozilla Foundation and its subsidiary, Mozilla Corporation. even when mozilla is (financially) having a tough time, security should be everyone’s top […]

Pwn2Own 2020: opening a pdf can be enough to compromise system! https://youtu.be/u1udr7j9MQA?t=359 90% of companies DO NOT NEED JavaScript or macros to run in PDF but still it is there… and Adobe knows about it: “JavaScripts in PDFs as a […]

new Russian IT Security updates: thanks to https://www.securitylab.ru/ and https://translate.yandex.com/   SecurityLab, [06.11.19 16:12] The Libarchive compression library, which is included by default in Debian, Ubuntu, Gentoo, Arch Linux, FreeBSD, and NetBSD distributions, contains a vulnerability that allows an attacker […]

about MAC address(es) not every switch has an IP assigned (if it has no web management interface, it does not need to) but it will have a MAC address. MAC address are per vendor and per device unique identifiers that […]

One way to do it is: while read p; do echo “$p” done <peptides.txt As pointed out in the comments, this has the side effects of trimming leading whitespace, interpretting backslash sequences, and skipping the trailing line if it’s missing […]

“In the popular series of wireless keyboards Fujitsu LX390 found two dangerous vulnerabilities. According to researchers from the company SySS, exploitation of vulnerabilities allows nearby attackers to “spy” passwords entered on the keyboard, or even to seize control of the […]